A genus of 7-9 species, herbs, endemic to e. and c. North America. There has been considerable medicinal use of extracts from many of the species, and collection of plants from the wild to meet the demand of the herbal trade has extirpated many populations, particularly in c. United States. Foster (1991) presents a lengthy and detailed discussion of medicinal uses of Echinacea, along with considerable information on the biology, conservation needs, taxonomy, and nomenclatural history of the genus. Binns, Baum, & Arnason (2002) provide no rationale for their approach of recognizing the same number of taxa as McGregor, but treating them as 4 species and 10 varieties; the entities seem to be distinct at the specific level.
Ref: Baskin, Snyder, & Baskin (1993); Binns, Baum, & Arnason (2002); Cronquist (1980); Foster (1991); Gaddy (1991); McGregor (1968); McKeown (1999); Urbatsch, Neubig, and Cox (2006) In Flora of North America Editorial Committee (2006c). Show full citations.